Axial-flow fan

Abstract

The present invention provides an axial-flow fan capable of entirely cooling an object to be cooled even when the distance between the object to be cooled and an air discharge opening of the axial-flow fan is short. A plurality of stationary blades 11 A to 11 E are disposed at intervals in a rotating direction of a rotor and located inside an air discharge opening 16 of an air channel 19 . Each of the plurality of stationary blades 11 A to 11 E has an external end portion 11 a connected to an inner wall portion of a fan housing 3 , an internal end portion 11 b connected to a peripheral wall portion 11 B of a motor case 10 , a discharge-side edge portion 11 c formed between the external end portion 11 a and the internal end portion 11 b and located at a side of the air discharge opening 16 , and a suction-side edge portion 11 d formed between the external end portion 11 a and the internal end portion 11 b and located at a side of the air suction opening 14 . An outer surface of the bottom wall portion 10 A of the motor case 10 is located closer to a side of the air suction opening 14 than the discharge-side edges 11 c of the plurality of stationary blades 11 A to 11 D are located.

1. An axial-flow fan comprising:
 a fan housing including an air channel having an air discharge opening and an air suction opening; 
 an impeller having a plurality of blades and disposed inside the fan housing; 
 a rotor to which the impeller is fixed; 
 a stator disposed corresponding to the rotor; 
 a motor case to which the stator is fixed, including a bottom wall portion located at a side of the air discharge opening and a peripheral wall portion formed continuously with the bottom wall portion and extending toward the air suction opening; and 
 a plurality of stationary blades disposed at intervals in a rotating direction of the impeller and located inside the air discharge opening of the air channel, each of the plurality of stationary blades connecting the peripheral wall portion of the motor case and the fan housing, each of the plurality of stationary blades having an external end portion connected to an inner wall portion of the fan housing, an internal end portion connected to the peripheral wall portion of the motor case, a discharge-side edge portion formed between the external end portion and the internal end portion and located at a side of the air discharge opening, and a suction-side edge portion formed between the external end portion and the internal end portion and located at a side of the air suction opening, 
 wherein an outer surface of the bottom wall portion of the motor case is located closer to the air suction opening than the discharge-side edge portions of all or most of stationary blades are located. 
 
   
   
     2. The axial-flow fan according to  claim 1 , wherein the outer surface of the bottom wall portion of the motor case is composed of a flat bottom surface and an outer peripheral surface portion continuous with the flat bottom surface, and the outer peripheral surface portion is gradually curved from the bottom surface toward an outer peripheral surface of the peripheral wall portion. 
   
   
     3. The axial-flow fan according to  claim 1 , wherein all or most of the plurality of stationary blades each include an extended portion extending on the bottom wall portion of the motor case, and the extended portion has a guide surface for guiding a part of air flowing along the stationary blades toward the bottom surface of the bottom wall portion. 
   
   
     4. The axial-flow fan according to  claim 3 , wherein the extended portion further has an extended guide surface formed continuously with the guide surface and extending toward the rotating direction. 
   
   
     5. The axial-flow fan according to  claim 2 , wherein all or most of the plurality of stationary blades each include an extended portion extending on the bottom wall portion of the motor case, and the extended portion has a guide surface for guiding a part of air flowing along the stationary blades toward the bottom surface of the bottom wall portion. 
   
   
     6. The axial-flow fan according to  claim 5 , wherein the extended portion further has an extended guide surface formed continuously with the guide surface and extending toward the rotating direction. 
   
   
     7. The axial-flow fan according to  claim 2 , wherein a dimensional difference in height between the bottom surface of the bottom wall portion and an edge of the discharge-side edge portion of the stationary blade is 3 mm or more. 
   
   
     8. The axial-flow fan according to  claim 1 , wherein the stationary blade is curved, in a convex manner, toward the rotating direction. 
   
   
     9. The axial-flow fan according to  claim 8 , wherein, among the plurality of stationary blades, a plurality of stationary blades each having an extended portion are generally inclined so that the discharge-side edge portions of the stationary blades are located more forward than the suction-side edges thereof in the rotating direction. 
   
   
     10. The axial-flow fan according to  claim 1 , wherein one stationary blade among the plurality of stationary blades has a groove portion that receives therein a plurality of lead wires for supplying electric power to the stator; the groove portion is opened toward the air discharge opening; the discharge-side edge portion of the one stationary blade is composed of two divided edges respectively located at either side of the groove portion in the rotating direction; and the two divided edges are inclined in the vicinity of the internal end portion so that the flat bottom surface of the bottom wall portion and the two divided edges are flush with each other. 
   
   
     11. An axial-flow fan comprising:
 a fan housing including an air channel having an air discharge opening and an air suction opening; 
 an impeller having a plurality of blades and disposed inside the fan housing; 
 a rotor to which the impeller is fixed; 
 a stator disposed corresponding to the rotor; 
 a motor case to which the stator is fixed, including a bottom wall portion located at a side of the air discharge opening and a peripheral wall portion formed continuously with the bottom wall portion and extending toward the air suction opening; and 
 a plurality of stationary blades disposed at intervals in a rotating direction of the impeller and located inside the air discharge opening of the air channel, each of the plurality of stationary blades connecting the peripheral wall portion of the motor case and the fan housing, each of the plurality of stationary blades having an external end portion connected to an inner wall portion of the fan housing, an internal end portion connected to the peripheral wall portion of the motor case, a discharge-side edge portion formed between the external end portion and the internal end portion and located at a side of the air discharge opening, and a suction-side edge portion formed between the external end portion and the internal end portion and located at a side of the air suction opening, one stationary blade among the plurality of stationary blades having a structure that receives therein a plurality of lead wires for supplying electric power to the stator, other stationary blades except for the one stationary blade being shaped so that the discharge-side edges thereof are located closer to the air discharge opening than an outer surface of the bottom wall portion of the motor case is located. 
 
   
   
     12. The axial-flow fan according to  claim 11 , wherein the outer surface of the bottom wall portion of the motor case is composed of a flat bottom surface and an outer peripheral surface portion continuous with the flat bottom surface, and the outer peripheral surface portion is gradually curved from the bottom surface toward an outer peripheral surface of the peripheral wall portion. 
   
   
     13. The axial-flow fan according to  claim 12 , wherein the other plurality of stationary blades each include an extended portion extending on the bottom wall portion of the motor case, and the extended portion has a guide surface for guiding a part of air flowing along the stationary blades toward the bottom surface of the bottom wall portion. 
   
   
     14. The axial-flow fan according to  claim 13 , wherein the extended portion further has an extended guide surface formed continuously with the guide surface and extending toward the rotating direction.